﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DotRas;
using System.Diagnostics;
using System.Text.RegularExpressions;

namespace TinyVpnPro
{
        public class VPNHelper
        {
            // 系统路径 C:\windows\system32\
            private static string WinDir = Environment.GetFolderPath(Environment.SpecialFolder.System) + @"";
            // rasdial.exe
            private static string RasDialFileName = "rasdial.exe";
            // VPN路径 C:\windows\system32\rasdial.exe
            private static string VPNPROCESS = WinDir + RasDialFileName;
            // VPN地址
            public string IPToPing { get; set; }
            // VPN名称
            public string VPNName { get; set; }
            // VPN用户名
            public string UserName { get; set; }
            // VPN密码
            public string PassWord { get; set; }

            public VPNHelper()
            {
            }
            /// <summary>
            /// 带参构造函数
            /// </summary>
            /// <param name="_vpnIP"></param>
            /// <param name="_vpnName"></param>
            /// <param name="_userName"></param>
            /// <param name="_passWord"></param>
            public VPNHelper(string _vpnIP, string _vpnName, string _userName, string _passWord)
            {
                this.IPToPing = _vpnIP;
                this.VPNName = _vpnName;
                this.UserName = _userName;
                this.PassWord = _passWord;
            }
            /// <summary>
            /// 尝试连接VPN(默认VPN)
            /// </summary>
            /// <returns></returns>
            public void TryConnectVPN()
            {
                this.TryConnectVPN(this.VPNName, this.UserName, this.PassWord);
            }
            /// <summary>
            /// 尝试断开连接(默认VPN)
            /// </summary>
            /// <returns></returns>
            public void TryDisConnectVPN()
            {
                this.TryDisConnectVPN(this.VPNName);
            }
            /// <summary>
            /// 创建或更新一个默认的VPN连接
            /// </summary>
            public void CreateOrUpdateVPN()
            {
                this.CreateOrUpdateVPN(this.VPNName, this.IPToPing);
            }
            /// <summary>
            /// 尝试删除连接(默认VPN)
            /// </summary>
            /// <returns></returns>
            public void TryDeleteVPN()
            {
                this.TryDeleteVPN(this.VPNName);
            }
            /// <summary>
            /// 尝试连接VPN(指定VPN名称，用户名，密码)
            /// </summary>
            /// <returns></returns>
            public void TryConnectVPN(string connVpnName, string connUserName, string connPassWord)
            {
                try
                {
                    string args = string.Format("{0} {1} {2}", connVpnName, connUserName, connUserName);
                    ProcessStartInfo myProcess = new ProcessStartInfo(VPNPROCESS, args);
                    myProcess.CreateNoWindow = true;
                    myProcess.UseShellExecute = false;
                    Process.Start(myProcess);
                }
                catch (Exception Ex)
                {
                    Debug.Assert(false, Ex.ToString());
                }
            }
            /// <summary>
            /// 尝试断开VPN(指定VPN名称)
            /// </summary>
            /// <returns></returns>
            public void TryDisConnectVPN(string disConnVpnName)
            {
                try
                {
                    string args = string.Format(@"{0} /d", disConnVpnName);
                    ProcessStartInfo myProcess = new ProcessStartInfo(VPNPROCESS, args);
                    myProcess.CreateNoWindow = true;
                    myProcess.UseShellExecute = false;
                    Process.Start(myProcess);

                }
                catch (Exception Ex)
                {
                    Debug.Assert(false, Ex.ToString());
                }
            }
            /// <summary>
            /// 创建或更新一个VPN连接(指定VPN名称，及IP)
            /// </summary>
            public void CreateOrUpdateVPN(string updateVPNname, string updateVPNip)
            {
                RasDialer dialer = new RasDialer();
                RasPhoneBook allUsersPhoneBook = new RasPhoneBook();
                allUsersPhoneBook.Open();
                // 如果已经该名称的VPN已经存在，则更新这个VPN服务器地址
                if (allUsersPhoneBook.Entries.Contains(updateVPNname))
                {
                    allUsersPhoneBook.Entries[updateVPNname].PhoneNumber = updateVPNip;
                    // 不管当前VPN是否连接，服务器地址的更新总能成功，如果正在连接，则需要VPN重启后才能起作用
                    allUsersPhoneBook.Entries[updateVPNname].Update();
                }
                // 创建一个新VPN
                else
                {
                    RasEntry entry = RasEntry.CreateVpnEntry(updateVPNname, updateVPNip, RasVpnStrategy.PptpFirst, RasDevice.GetDeviceByName("(PPTP)", RasDeviceType.Vpn));
                    allUsersPhoneBook.Entries.Add(entry);
                    dialer.EntryName = updateVPNname;
                    dialer.PhoneBookPath = RasPhoneBook.GetPhoneBookPath(RasPhoneBookType.AllUsers);
                }
            }
            /// <summary>
            /// 删除指定名称的VPN
            /// 如果VPN正在运行，一样会在电话本里删除，但是不会断开连接，所以，最好是先断开连接，再进行删除操作
            /// </summary>
            /// <param name="delVpnName"></param>
            public void TryDeleteVPN(string delVpnName)
            {
                RasDialer dialer = new RasDialer();
                RasPhoneBook allUsersPhoneBook = new RasPhoneBook();
                allUsersPhoneBook.Open();
                if (allUsersPhoneBook.Entries.Contains(delVpnName))
                {
                    allUsersPhoneBook.Entries.Remove(delVpnName);
                }
            }
            /// <summary>
            /// 获取当前正在连接中的VPN名称
            /// </summary>
            public List<string> GetCurrentConnectingVPNNames()
            {
                List<string> ConnectingVPNList = new List<string>();
                Process proIP = new Process();
                proIP.StartInfo.FileName = "cmd.exe ";
                proIP.StartInfo.UseShellExecute = false;
                proIP.StartInfo.RedirectStandardInput = true;
                proIP.StartInfo.RedirectStandardOutput = true;
                proIP.StartInfo.RedirectStandardError = true;
                proIP.StartInfo.CreateNoWindow = true;//不显示cmd窗口
                proIP.Start();
                proIP.StandardInput.WriteLine(RasDialFileName);
                proIP.StandardInput.WriteLine("exit");
                // 命令行运行结果
                string strResult = proIP.StandardOutput.ReadToEnd();
                proIP.Close();
                // 用正则表达式匹配命令行结果，只限于简体中文系统哦^_^
                Regex regger = new Regex("(?<=已连接\r\n)(.*\n)*(?=命令已完成)", RegexOptions.Multiline);
                // 如果匹配，则说有正在连接的VPN
                if (regger.IsMatch(strResult))
                {
                    string[] list = regger.Match(strResult).Value.ToString().Split('\n');
                    for (int index = 0; index < list.Length; index++)
                    {
                        if (list[index] != string.Empty)
                            ConnectingVPNList.Add(list[index].Replace("\r", ""));
                    }
                }
                // 没有正在连接的VPN，则直接返回一个空List<string>
                return ConnectingVPNList;
            }
        }
    
}
